diff --git a/Packages/ComposeUI/Sources/ComposeUI/Controllers/ComposeController.swift b/Packages/ComposeUI/Sources/ComposeUI/Controllers/ComposeController.swift
index c1d645c0..93682956 100644
--- a/Packages/ComposeUI/Sources/ComposeUI/Controllers/ComposeController.swift
+++ b/Packages/ComposeUI/Sources/ComposeUI/Controllers/ComposeController.swift
@@ -58,7 +58,7 @@ public final class ComposeController: ViewController {
     private var isDisappearing = false
     private var userConfirmedDelete = false
     
-    var isPosting: Bool {
+    public var isPosting: Bool {
         poster != nil
     }
     
@@ -424,6 +424,7 @@ public final class ComposeController: ViewController {
                     // otherwise all Buttons in the nav bar are made semibold
                     .font(.system(size: 17, weight: .regular))
             }
+            .disabled(controller.isPosting)
             .confirmationDialog("Are you sure?", isPresented: $controller.isShowingSaveDraftSheet) {
                 // edit drafts can't be saved
                 if draft.editedStatusID == nil {
diff --git a/Tusker/Screens/Compose/ComposeHostingController.swift b/Tusker/Screens/Compose/ComposeHostingController.swift
index 6259771d..6e8e7580 100644
--- a/Tusker/Screens/Compose/ComposeHostingController.swift
+++ b/Tusker/Screens/Compose/ComposeHostingController.swift
@@ -144,7 +144,9 @@ class ComposeHostingController: UIHostingController<ComposeHostingController.Vie
     // MARK: Duckable
     
     func duckableViewControllerShouldDuck() -> DuckAttemptAction {
-        if controller.draft.hasContent {
+        if controller.isPosting {
+            return .block
+        } else if controller.draft.hasContent {
             return .duck
         } else {
             return .dismiss